Correction Factor:

These sensors are mainly used to
differentiate Light and Dark colours.
Emitter and Receiver are enclosed in a
single housing. The transmitted light
beam is reflected by the light colour and
it returns to the receiver. When the dark
colour mark enters into this light beam,
the receiver senses the changes in colour
by reflection.

Photo Electronic Sensors are used to sense all kinds of objects at higher sensing distance
compared to lnductive Proximity Switches and Capacitive Proximity Switches.

Photo Electronic Sensor consists of an Emitter, a Receiver and an Amplifier. Pulsed Infra-Red light beam is generated by the Emitter. This effective beam is reflected either by an object or by a reflector (depending on the type of sensor) and it returns to the receiver. The receiver converts the reflected incoming light signal into electrical signal and the built-in amplifier amplifies the electrical signal. The amplified signal drives output transistor (either NPN or PNP) which in turn drives an electronic circuit or a relay. Either of the following three types of photo electronic sensors can be used can be used to sense an object based on their sizes and colours.

Emitter and Receiver are
enclosed in different housing. The
beam f rom the Emitter directly
reaches t he Receiver . Any
inter rupt ion in the beam results in switching action.

Diffuse Reflective Type

Both Emitter and Receiver are
enclosed in a single housing. Infrared light beam form emitter is
reflected by an object . T h i s
ref lected beam causes a change
in receiver and produces an
output signal.

Retro Relective Type

Emitter and Receiver are enclosed
in a single housing and are aligned
with a reflector. A continuous beam
of light from the reflector reaches
the receiver. Any interruption in the
beam will result in an output signal
from the receiver.